Organophilic modified polymers

ABSTRACT

Organophilic polymer adducts which are effective fluid loss control additives for oil base well-working fluids are prepared from an anionic or cationic water soluble polymer and one or more phosphatides. Preferred phosphatides are phosphoglycerides obtained from vegetable oils, most preferably commercial lecithin. Preferred polymers comprise polysaccharides or derivatives thereof and synthetic polymers.

FIELD OF THE INVENTION

The invention relates to organophilic derivatives of polymers, tomethods for their manufacture, and to their use in oil base well workingfluids.

BACKGROUND OF THE INVENTION

In the drilling of wells for oil and gas by the rotary method, it iscommon to use a circulating fluid which is pumped down to the bottom ofthe well through a drill pipe, where the fluid emerges through ports inthe drilling bit. The fluid rises to the surface in the annular spacebetween the drill pipe and the walls of the hole, and at the surface itis treated to remove cuttings and the like to prepare it forrecirculation into the drill pipe. The circulation is substantiallycontinuous while the drill pipe is rotated.

The present invention pertains to oil base drilling fluids or oil basemuds which includes water-in-oil (invert) emulsions as well as oil basefluids containing only small amounts or no emulsified water.

An important feature of well working fluids of the class described istheir ability to resist filtration. In most instances, when they are inactual use, whether as drilling fluids, packer fluids, fracturing orcompletion fluids, the well working fluid is in contact with a more orless permeable formation, such as, for example, sandstone, sandy shaleand the like, with an effective balance of pressure such that the fluidtends to be forced into the permeable formation. When a well workingfluid is deficient in its ability to resist filtration, then the solidsin the fluid are held back by the permeable formation and build up as afilter cake or sludge on its surfaces, while the liquid per se of thewell working fluid filters into the permeable formation. The filter cakeor sludge thus formed is generally very undesirable. Moreover, the lossof oil to the formation is very expensive, not only because of the costof the oil itself, but also due to the cost of maintaining theproperties and composition of the fluid.

Various additives have been used or suggested for use as fluid lossadditives to prevent or decrease this loss of fluid by filtration fromoil base muds. Some of the first materials used for this purpose wereasphalt and various modified asphaltic materials. The following patentsdisclose various amine derivatives of various polyphenolic compounds foruse as fluid loss control additives (hereinafter sometimes referred toas FLCA) for oil muds: Jordan et al. U.S. Pat. No. 3,168,475; Jordan etal. U.S. Pat. No. 3,281,458; Beasley et al. U.S. Pat. No. 3,379,650;Cowan et al. U.S. Pat. No. 3,232,870; Cowan et al. U.S. Pat. No.3,425,953; Andrews et al. U.S. Pat. No. 3,494,865; Andrews et al. U.S.Pat. No. 3,671,427, Andrews et al. U.S. Pat. No. 3,775,447; Kim U.S.Pat. No. 3,538,071; Kim U.S. Pat. No. 3,671,428; Cowan U.S. Pat. No.4,421,655; Connell et al. 4,501,672; and Frost European PatentApplication 049,484.

As noted in the examples in the aforementioned patents, the amount ofthe organic amine or amide compounds reacted with the polymeric phenoliccompounds disclosed is quite high, generally of the order of 75%-100% ormore, based on the weight of the polymeric phenolic compound, althoughamounts from 20% to 200% are disclosed to be useful. Most of these FLCApossess poor dispersibility in well working fluids unless elaborateprocedures are undertaken, such as the addition of a dispersant,heating, agitating under high shear or for extended periods of time,drying under low temperature conditions, flushing, preparation inoleaginous liquids, and the like. Moreover, the amine and amidecompounds are relatively expensive to prepare and/or purchase, and thusthese FLCA are quite expensive to produce.

SUMMARY OF THE INVENTION

We have now found that organophilic derivatives of water solublepolymers can be prepared by reaction of the polymer with a phosphatide,preferably commercial lecithin. These phosphatide/polymer adducts areorganophilic, and have been found to be fluid loss additives for oilbased well working fluids.

PREFERRED EMBODIMENTS OF THE INVENTION

The novel FLCA of this invention comprises an organophilic materialwhich is a phosphatide derivative of a water soluble polymer.

The organophilic phosphatide which is useful in the practice of theinvention is one or more phosphatides having the empirical formula

    R.sub.1 --CO--O--CH.sub.2 --CH(R.sub.2)--CH.sub.2 --Q      (I)

where R₁ is an aliphatic group containing from 8 to 29 carbon atoms; R₂is selected from the group consisting of H, OH, R₁ COO, and OP(O)(O⁻zM^(a+))OZ; Q is selected from the group consisting of R₁ COO, andOP(O)(O⁻ zM^(a+))OZ; Z is selected from the group consisting of xM^(a+),C₆ H₆ (OH)₅ and CH₂ --CH(Y)--N(R₃)(R₄)(R₅)_(y) (A^(b-))_(v) ; Y isselected from the group consisting of H and COO(wM^(a+)); R₃, R₄, and R₅are independently selected from the group consisting of H, aliphaticgroups containing from 1 to 30 carbon atoms, and R₆ CO; R₆ is analiphatic group containing from 1 to 29 carbon atoms; M is a cationselected from the group consisting of H, an alkali metal, an alkalineearth metal, ammonium, and mixtures thereof; A is an anion of valence b;y= 0 or 1; w, x, and z=0 or 1/a where a is the valence of M; v=0 or 1/b;and where Q is R₁ COO only when R₂ is OP(O)(O⁻ zM^(a+))OZ.

Preferably R₁ contains from about 15 to about 17 carbon atoms, R₂ isselected from the group consisting of R₁ COO and OP(O)(O⁻ zM^(a+))OZ;and R₃, R₄, and R₅ are independently selected from the group consistingof H, CH₃, and R₁ CO.

Such phosphatides are present in amounts up to about 5% by weight incertain crude vegetable oils, which are principally triglycerides offormula (I) wherein both R₂ and Q are R₁ COO where R₁ is an aliphaticgroup containing from about 15 to about 17 carbon atoms. Variousrefining procedures, well known in the art, may be utilized to isolatethe various individual phosphatides or to concentrate the phosphatidesas a group (mixture of phosphatides). Thus crude commercial lecithinfrom soybean oil contains from about 30% to about 50% by weighttriglyceride and from about 50% to about 70% by weight of a mixture ofphosphatides, principally phosphatidyl choline (α-form and β-form),phosphatidyl ethanolamine (α-form and β-form), N-Acyl phosphatidylethanolamine (α-form and β-form), phosphatidyl serine (α-form andβ-form), phosphatidyl inositol (α-form and β-form), phosphatidic acid,minor amounts of various other phosphatides, or the alkali metal oralkaline earth metal salts thereof. In the α-form the phosphate estergroup OP(O)(O⁻ zM^(a+))OZ is on the end carbon (Q) whereas in the β-formthe phosphate ester group is on the middle carbon atom (R₂ group).

Thus preferably the organophilic phosphatide is a mixture ofphosphatides having the empirical formula

    R.sub.1 COO--CH.sub.2 --CH(R.sub.2)--CH.sub.2 --Q          (II)

where R₁ is an aliphatic group containing from about 15 to about 17carbon atoms; R₂ =c R₁ COO+d OP(O)(O⁻ zM^(a+))OZ; Q=d R₁ coo+c OP(O)(O⁻zM^(a+))OZ; Z is selected from the group consisting of xM^(a+), C₆ H₆(OH)₅ and CH₂ --CH(Y)--N(R₃)(R₄)(R₅)_(y) (A^(b-))_(v) ; Y is selectedfrom the group consisting of H and COO(wM^(a+)); R₃, R₄, and R₅ areindependently selected from the group consisting of H, CH₃, and R₁ CO; Mis a cation selected from the group consisting of H, an alkali metal, analkaline earth metal, ammonium, and mixtures thereof; y=0 or 1; A is ananion of valence b; w, x, and z=0 or 1/a where a is the valence of M;v=0 or 1/b; c≧0; d≧0; and c+d=1.

Such phosphatides wherein: Z=CH₂ CH₂ N(CH₃)₃ are called phosphatidylcholine (or lecithin); Z=CH₂ CH₂ NH₃ or CH₂ CH₂ NH₂ are calledphosphatidyl ethanolamine (or cephalin); Z=CH₂ CH(COO⁻)NH₃ or CH₂CH(COOH)NH₂ are called phosphatidyl serine; Z=CH₂ CH₂ NH--CO--R₁ arecalled N-Acylphosphatidyl ethanolamine; Z=C₆ H₆ (OH)₅ are calledphosphatidyl inositol; and Z=H are called phosphatidic acid. The amountsof these phosphatides which are present in the phosphatide mixture ofvarious vegetable oils have been variously disclosed to be as follows:

    ______________________________________                                                % Phosphatide, Based on the                                                   Weight of all Phosphatides, in                                                  Soybean  Corn     Cottonseed                                                                            Sunflower                                 Phosphatide                                                                             Oil      Oil      Oil     Oil                                       ______________________________________                                        Choline   28-32    41-46    0-33    52                                        ethanolamine                                                                            12-31    4-5      19-39   20                                        inositol  20-32    19-23    6-37    26                                        serine    --       0-3      0-33    --                                        acid      --       14-16    --      2                                         other     15-18    12-16    8-25    --                                        ______________________________________                                    

Thus a preferred phosphatide mixture suitable for use in this inventioncontains from about 0% to about 52% phosphatidyl choline, from about 4%to about 39% phosphatidyl ethanolamine, from about 6% to about 37%phosphatidyl inositol, from about 0% to about 33% phosphatidyl serine,from about 0% to about 16% phosphatidic acid, and from about 0% to about25% of various other phosphatides. The most preferred phosphatidemixture is commercial soybean lecithin.

The organophilic modifier useful in this invention preferably containsfrom about 50% to about 100% by weight of organophilic phosphatides andfrom about 0% to about 50% by weight of a vegetable oil triglyceride.Most preferably the organophilic modifier is commercial lecithin whichcontains from about 30% to about 50% of the vegetable oil from which thelecithin is concentrated, from about 35% to about 70% of a mixture ofphosphatides having the empirical formula

    R.sub.1 --CO--O--CH.sub.2 --CH(R.sub.2)--CH.sub.2 --Q      (III)

where: R₁ is an aliphatic group containing from about 15 to about 17carbon atoms; R₂ is selected from the group consisting of R₁ COO andOP(O)(O⁻ zM^(a+))OZ; Q is selected from the group consisting of R₁ COOand OP(O)(O⁻ zM^(a+))OZ; Z is selected from the group consisting ofxM^(a+), C₆ H₆ (OH)₅, and CH₂ --CH(Y)-N(R₃)(R₄)(R₅)_(y) (A^(b-))_(v) ; Yis selected from the group consisting of H and COO(wM^(a)); R₃, R₄, andR₅ are independently selected from the group consisting of H, CH₃, andR₁ CO; M is a cation selected from the group consisting of H, an alkalimetal, an alkaline earth metal, ammonium, and mixtures thereof; A is ananion of valence b; y=0 or 1; w, x and z=0 or 1/a where a is the valenceof M; v=0 or 1/b; and Q is R₁ COO only when R₂ is OP(O)(O⁻ zM^(a+))OZ;and from 0% to about 18% of other phosphatides.

While the ammonium-containing phosphatides may be in the internallyneutralized zwitterionic form (i.e., v=o, y=1, and either w=0 or z=0),it is believed that such phosphatides react with the polymers bysubstitution because of the insolubility of the resulting organophilicpolymer adduct. Regardless of the mechanism of the formation of theorganophilic polymeric material, there is formed a phosphatide-polymeradduct which is an effective fluid loss additive for oil base wellworking fluids.

The water soluble polymers which may be modified in accordance with thisinvention include polysaccharides or polysaccharide derivatives andsynthetic polymers. The term "polysaccharide or polysaccharidederivative" is used conventionally herein and refers generally topolysaccharides (i.e., polymers comprised of monosaccharide units linkedtogether by glycosidic bonds) or chemical modifications ofpolysaccharides which polysaccharides or chemical modifications thereofare soluble in one or more aqueous liquids. By the term "water soluble"is meant that the polymer is capable of being admixed with water underappropriate temperature and pH conditions such that the resultingmixture appears as a homogeneous liquid under visual inspection with nomagnification. Thus, water soluble polymers may form true solutions inwater, colloidal dispersions in water, or emulsions in water.

Polymers which are suitable for use in accordance with the presentinvention are either anionic or cationic. Anionic polymers will contain,in sufficient concentration and reactive position, one or more of thefunctional groups carboxyl, sulfate, or sulfonate. Cationic polymerswill contain, in sufficient concentration and reactive position, one ormore of the functional groups amine, quaternary ammonium, or quaternaryphosphonium.

Particularly suitable polymers are polysaccharides which contain one ormore of the following monosaccharide units: arabinose, fructose,galactose, galactopyranosyl, galacturonic acid, guluronic acid,glucuronic acid, glucose, glucoside, N-acetylglucosamine, mannuronicacid, mannose, pyranosyl sulfate, rhamnose, or xylose. Polysaccharidescontaining the foregoing units include alginic acid, agar, carrageean,cellulose, chitin, guar gum, gum arabic, gum ghatti, gum karaya, gumkonjak, gum tamarind, gum tara, gum tragacanth, locust bean gum,pectins, starch, and xanthan gum. Polysaccharides which are eitheranionic or cationic include the natural polysaccharides alginic acid,carrageenan, chitosan (partially deacetylated chitin), gum arabic, gumghatti, gum karaya, gum tragacanth, pectins, and xanthan gum, andderivatives of all of the polysaccharides listed in the preceedingsentence containing one or more of the functional groups carboxyl,sulfate, sulfonate, amine, quaternary ammonium, or quaternaryphosphonium. Derivatization of polysaccharides to incorporate thedesired functional group therein is well known in the art and referenceis made thereto for the purposes of this invention.

Thus representative polysaccharide derivatives include carboxymethylethers, carboxyethyl esters, sulfate esters, methylsulfonic acid ethers,dialkylaminoalkyl ethers, dialkylphosphonoalkyl ethers,dialkylaminoalkyl ethers quaternized with dimethyl sulfate or methylchloride, hydroxyalkyl (i.e. hydroxyethyl and hydroxypropyl)carboxyalkyl ethers, hydroxyalkyl ether sulfate esters, hydroxyalkylmethylsulfonic acid ethers, hydroxyalkyl dialkylaminoalkyl ethers,hydroxyalkyl dialkylphosphonoalkyl ethers, hydroxyalkyldialkylaminoethyl ethers quaternized with dimethyl sulfate or methylchloride, and grafted polysaccharide polymers containing one or moreunsaturated monomers grafted onto the polysaccharide. Representative ofsuch monomers include acrylamide, methacrylamide, acrylic acid,methacrylic acid, aminoalkylacrylates, aminoalkylmethacrylates,dialkylaminoalkyl acrylates, dialkylaminoalkyl methacrylates, vinylsulfonate, vinyl benzyl dimethyl ammonium chloride,2-sulfoethylacrylate, vinyl benzyl sulfonates,2-acrylamido-2-methylpropane sulfonic acid, quaternized salts of theamino-containing monomers with dimethyl sulfate or methyl chloride, andthe like.

The solubility of the aforementioned polysaccharides and derivativesthereof is dependent upon a variety of factors including the averagedegree of polymerization and, in the case of polysaccharide derivatives,the particular substituent and the degree of substitution, i.e., thenumber of substituent groups per anhydroglucose unit of thepolysaccharide molecule. In general, the relative solubility of thepolysaccharide in an aqueous liquid increases as the molecular weightdecreases. Additionally, a polysaccharide derivative having a low degreeof substitution may only be soluble in alkaline aqueous liquid, whereasa polysaccharide derivative having a higher degree of substitution maybe soluble in water as well as an alkaline aqueous liquid. Theparticular substituent and the degree of substitution which imparts thedesired solubility to the polysaccharide derivatives are well known inthe art and reference is made thereto for the purposes of thisinvention.

Anionic and cationic synthetic water soluble polymers may also bemodified in accordance with this invention.

Anionic polymers can be prepared by reacting under polymerizingconditions ethylenically unsaturated acid(s) with non-ionicethylenically unsaturated monomers. Cationic polymers can be prepared byreacting under polymerizing conditions ethylenically unsaturated aminoor ammonium monomer(s) with non-ionic ethylenically unsaturatedmonomers.

The ethylenically unsaturated acid is used to introduce an acidic groupinto the resulting copolymer. It includes compounds having at least one,preferably only one, radical-polymerizable ethylenically unsaturatedbond (>C═C<) and at least one, preferably 1 or 2, acid functional groupssuch as carboxyl or sulfo groups, per molecule. Preferred examples arecompounds of the following general formula ##STR1## wherein R₁represents a hydrogen atom, a lower alkyl group or a carboxyl group, R₂represents a hydrogen atom, a lower alkyl group or a carboxymethylgroup, and Y represents a carboxyl group, a sulfo group, a sulfomethylgroup (--CH₂ SO₃ H) or a sulfophenyl group ##STR2## Specific examples ofthe ethylenically unsaturated acid include ethylenically unsaturatedmonocarboxylic acids having 3 to 10 carbon atoms, such as acrylic acid,methacrylic acid and crotonic acid; ethylenically unsaturateddicarboxylic acids having 4 to 12 carbon atoms, such as maleic acid,fumaric acid, an itaconic acid, or their monoalkyl (C₁₋₈) esters; andethylenically unsaturated monosulfonic acids such as allylsulfonic acid,styrenesulfonic acid and a-methylstyrenesulfonic acid. Acrylic acid andmethacrylic acid are especially preferred.

The term "lower", as used in the present specification and the appendedclaims, means that groups or compounds qualified by this term have notmore than 6, preferably not more than 4, carbon atoms.

These ethylenically unsaturated acids can be used either singly or incombination.

The ethylenically unsaturated amino or ammonium monomer is used tointroduce a cationic group into the resulting copolymer.

Useful water soluble cationic vinyl monomers include

(1) N-substituted (N'-dialkylaminoalkyl)

acrylamides such as:

N-(diethylaminomethyl)acrylamide,

N-(diethylaminomethyl)methacrylamide,

N-(dimethylaminomethyl)acrylamide,

N-(dipropylaminomethyl)acrylamide,

N-(piperidylmethyl)acrylamide:

(2) Aminoalkylacrylates and dialkylaminoalkylacrylates such as:

Diethylaminopropylacrylate,

Dimethylaminoethylacrylate,

Dimethylaminopropylacrylate;

(3) Vinylpyridine;

(4) Diallylamines such as:

Diallylbenzylamine,

Diallylmethylamine,

Diallylethylamine;

(5) Quaternaries such as:

Acrylamidopropylbenzyldimethylammonium hydroxides,

N-methyl-vinylpyridinium chloride,

Diallyldimethylammonium chloride,

Diallyldiethylammonium chloride,

Acrylopropylbenzyldimethylammonium hydroxide.

Quaternaries having at least one ethylenically unsaturated substituentmay also be prepared using members of groups (1), (2), (3), (4) and thelike.

The non-ionic ethylenically unsaturated monomer which can becopolymerized with the ethylenically unsaturated acid or theethylenically unsaturated amino or ammonium monomer includes aliphatic,cyclic, or heterocyclic compounds, or mixtures thereof, which contain atleast 1, preferably 1 or 2, radical polymerizable ethylenicallyunsaturated bonds per molecule and usually 2 to 26, preferably 3 to 21,carbon atoms and have a relatively low molecular weight. Specificexamples are given below.

(A) Acrylic or methacrylic acid esters

C₁₋₁₈ alkyl or cycloalkyl esters of acrylic or methacrylic acid such asmethyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate,butyl acrylate, hexyl acrylate, octyl acrylate, lauryl acrylate,cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, propylmethacrylate, isopropyl methacrylate, butyl methacrylate, hexylmethacrylate, octyl methacrylate, lauryl methacrylate and cyclohexylmethacrylate; C₂₋₁₂ alkoxyalkyl esters of acrylic or methacrylic acidsuch as methoxybutyl acrylate, methoxybutyl methacrylate, methoxyethylacrylate, methoxyethyl methacrylate, ethoxybutyl acrylate andethoxybutyl methacrylate; C₂₋₈ hydroxyalkyl esters of acrylic ormethacrylic acid such as hydroxyethyl acrylate, hydroxyethylmethacrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate andhydroxypropyl methacrylate; monoesters of acrylic or methacrylic acidwith (poly) C₁₋₁₂ alkylene glycols, such as ethylene glycol,polyethylene glycol, propylene glycol, polypropylene glycol or butyleneglycol, or their C₁₋₁₂ alkyl ethers; glycidyl acrylate, glycidylmethacrylate or adducts formed between glycidyl acrylate or methacrylatewith C₂₋₁₈ saturated or unsaturated monocarboxylic acids (e.g., aceticacid, propionic acid, stearic acid, linoleic acid, lauric acid, oleicacid, or linolenic acid); and conden-sation products formed betweenC₂₋₁₈ saturated or unsaturated monocarboxylic acids and C₁₋₁₄hydroxyalkyl esters of acrylic or methacrylic acid such as hydroxyethylmethacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate orhydroxypropyl methacrylate.

(B) Vinyl aromatic compounds

Styrene, α-methylstyrene, vinyltoluene, p-chlorostyrene, andvinylpyridine.

(C) Diolefinic compounds

Diolefins having 4 to 5 carbon atoms, such as butadiene, isoprene, andchloroprene.

(D) Monolefinic compounds

C₂₋₈ monolefins such as ethylene, propylene and butene.

(E) Acrylic or methacrylic amide

Acrylamide, methacrylamide, N-methylol acrylamide, and N-butoxymethylacrylamide.

(F) Ethylenically unsaturated nitriles Acrylonitrile andmethacrylonitrile.

(G) Vinyl esters of carboxylic acids

Vinyl acetate, vinyl propionate, and Veova monomer (a trademark for aproduct of Shell Chemical Co.).

(H) Other ethylenically unsaturated monomers

Methylisopropenyl ketone, vinyl chloride, vinylidene chloride, anddi(C₁₋₈ alkyl) esters of maleic acid.

Among these ethylenically unsaturated monomers, acrylic or methacrylicacid esters are especially preferred for use in this invention.

The above non-ionic ethylenically unsaturated monomers may be usedsingly or in a combination of two or more.

Generally speaking, the organophilic polymers of this invention may beproduced by bringing together the water soluble polymer in either acidor base form and the phosphatide in its base or acid form, respectively.The basic groups and the acidic groups are believed to neutralize eachother with salt formation and the large organophilic portion of thephosphatide and any organophilic carrier such as vegetable oiltriglycerides are sorbed onto the surface of the polymeric material toform the organophilic polymer material. The polymer may be converted toa water soluble or colloidally dispersible salt by reaction with asuitable base, generally an alkali metal, alkaline earth metal, orammonium base, most preferably an alkali metal base such as sodiumhydroxide, potassium hydroxide, and the like, or a basic salt such as analkali metal borate, carbonate, and the like salts as is well known inthe art. The phosphatide is then caused to be present in the form of asimple salt. Thus the amine groups in the phosphatide may be reactedwith an acid such as hydrochloric, acetic, phosphoric, sulfuric and thelike to give the corresponding ammonium salt.

For the preparation of solid, particulate organophilic polymer adductsof this invention, it is generally sufficient to insure intimate contactof the polymer and the phosphatide. Generally intensive mixing issufficient for reaction. Suitable intensive mixers which are capable ofhandling semi-solid materials are pug mills, extruders, ribbon blenders,Littleford Bros. mixer, Martin mixer, and the like apparatus. Watercontents less than about 60% by weight of the organophilic polyphenolicadduct will generally produce a semi-solid material. Thereafter theorganophilic polyphenolic adduct is preferably dried to less than about20% water and ground to produce a free-flowing powder. Alternatively,higher water contents generally produce slurries of the organophilicpolyphenolic adduct from which the adduct may be recovered by spraydrying, filtration, and the like known processes.

In a preferred slurry process, the polymer is dispersed in hot waterwith an alkali metal base to form a basic solution, suspension, oremulsion, the phosphatide added, and at least sufficient acid added toneutralize the alkali metal base.

The organophilic polymer materials can be prepared in the presence of anorganic liquid rather than an aqueous liquid. Thus the polymer and thephosphatide can be reacted together such as by high shear mixing attemperatures up to the boiling point of the mixture in various organicliquids, such as petroleum oils or refined fractions thereof, generallyparaffinic, aromatic, and naphthenic hydrocarbons of various molecularweights, or mixtures thereof. In this process the phosphatide can becaused to be present in an amount in excess of the amount required toform the organophilic polymer adduct. There is thus obtained a mixtureof the organophilic polymer adduct and the phosphatide in the organicliquid. Such a mixture can be used as a combination additive in oil basedrilling fluids to decrease the fluid loss and decrease the tendency ofinert solids in the drilling fluid to water wet.

The minimum amount of phosphatide reacted with the polymer need only besufficient to render the polymer organophilic. For the purposes of thisinvention, the polymer is considered organophilic when it is wetted bythe organic liquid when admixed with a mixture of water and an insolubleorganic liquid. Generally depending upon the particular polymer and itsmethod of preparation, the minimum amount of phosphatide will be about2.5% by weight based on the weight of the polymer. The maximum amount ofphosphatide reacted with the polymer is limited by the method ofpreparation and the characteristics of the polyphenolic material sinceconcentrations of phosphatides in excess of that required to react bycharge neutralization and surface adsorption provide enhancedorganophilic properties. Thus when utilizing a high shear, semi-solidprocess as disclosed hereinbefore, the maximum amount of phosphatidewhich may be caused to be present in the organophilic polyphenolicmaterial will be about 100% by weight, based on the weight of thepolymer. Amounts of phosphatide substantially above this 100% by weightmay produce a sticky, gummy solid which cannot be easily handled. Whenutilizing a slurry-type process, the maximum amount of phosphatide willbe in the range from about 50% to about 100% by weight, based on theweight of the polymer, depending on the particular characteristics ofthe polymer and its purity.

When utilizing commercial lecithin as the phosphatide, which containsfrom about 30% to about 50% by weight of the vegetable oil from whichthe phosphatide is obtained, there is preferably utilized from about 5%to about 150% commercial lecithin, based on the weight of the moisturefree-polymer, most preferably from about 10% to about 50% based on theweight of the moisture free-polymer.

It may be desired to improve the dispersibility or solubility of theorganophilic polymers in certain oleaginous liquids by incorporatingtherein one or more nitrogen-containing organic compounds containing atleast one alkyl, alkenyl, or acyl radical having from about 16 to about30 carbon atoms in a straight chain such as the amines, amine salts,quaternary ammonium compounds, amides, and amide-amines (partial amides)disclosed in the prior art for the modification of the polyphenolicmaterials. Exemplary of such nitrogen-containing organic compounds are:

(i) fatty ammonium compounds having the empirical formula

    R.sub.1 R.sub.2 R.sub.3 R.sub.4 N.sup.+A-

where: R₁, R₂, and R₃ are independently selected from the groupconsisting of H, aliphatic groups containing from 1 to about 30 carbonatoms, and benzyl; R₄ is an aliphatic group containing from about 16 toabout 30 carbon atoms; and A⁻ is a charge balancing anion, preferably ahalogen, most preferably chloride;

(ii) fatty polyamides or amide-amines which are the reaction products ofa fatty acid or fatty acid derivative with an alkylene diamine orpolyalkylene polyamine containing up to about 9 amine groups, having theempirical formula

    R.sub.1 R.sub.2 N[(CH.sub.2).sub.n --N(R.sub.2)].sub.x (CH.sub.2).sub.n --NHR.sub.2

where: R₁ is H, C₂₋₆ hydroxyalkyl, or an aliphatic group containing from1 to 30 carbon atoms; R₂ is selected from the group consisting of H andR₃ CO; R₃ is an aliphatic group containing from about 15 to about 29carbon atoms; n is an integer from 2 to 6, preferably 2 or 3; x is 0 oran integer from 1 to about 7; provided that at least one R₂ radical isR₃ CO; and

(iii) mixtures thereof.

The preferred amount of the nitrogen-containing organic compoundincorporated into the organophilic polymers of this invention is from 0%to about 50% by weight, based on the weight of the polymer, mostpreferably from about 2% to about 25% by weight.

Additionally, it may be desirable to improve the dispersibility orsolubility of the organophilic polyphenolic material of this inventionin certain oleaginous liquids by incorporating therein a polyvalentmetallic cation compound. Non-limiting illustrative examples of suitablepolyvalent cation compounds include calcium oxide, calcium hydroxide,calcium chloride, calcium acetate, calcium bromide, magnesium chloride,magnesium oxide, magnesium hydroxide, magnesium sulfate, ferricchloride, ferrous sulfate, zinc chloride, zinc sulfate, nickelicchloride, chronic chloride, aluminum chloride, aluminum sulfate, and thelike. The preferred polyvalent cation compound is selected from thegroup consisting of calcium oxide, calcium hydroxide, magnesium oxide,magnesium hydroxide, and mixtures thereof, most preferably calciumhydroxide.

The preferred amount of the polyvalent cation compound incorporated intothe organophilic polymer of this invention is from 0% to about 15% byweight based on the weight of the moisture-free organophilic polymermaterial, most preferably from about 2% to about 10%.

In a most preferred embodiment of this invention, there is added to theorganophilic polymer of the invention, before drying thereof, a soliddiluent in an amount sufficient to improve the handling characteristicsof the material. Suitable diluents which may be used, for example andnot by way of limitation, are clays such as kaolin, diatomaceous earth,silica, calcium carbonate, ground vegetable by-products such as bagasseand cotton linters, and the like. The preferred diluent is ahydrophobic, organophilic, water wettable fibrous material as disclosedin Cowan et al. U.S. Pat. No. 4,428,843, incorporated herein byreference, most preferably the hydrophobic, organo-philic, waterwettable cotton as disclosed in Cowan et al. U.S. Pat. No. 4,404,107,incorporated herein by reference.

The amount of the solid diluent added to the organophilic polymer willgenerally range from 0% up to about 35% by weight of the moisture-freeorganophilic polymer, preferably in the range from about 5% to about25%.

The organophilic polymeric adducts of this invention may be used asfluid loss control additives in oil based well working fluids. They maybe used as produced, but preferably after drying and grinding asdisclosed hereinbefore. The FLCA are solublized or dispersed in oil basewell-working fluids with the normal agitation available where suchfluids are prepared, such as at liquid "mud" plants or at the locationwhere the well-working fluid will be used.

The oil which forms a continuous phase of the well-working fluid is apetroleum (mineral) oil, and most generally is an ordinary diesel oil,although it may be rather lighter, such as kerosene, or somewhatheavier, such as fuel oil, white oils, or crude oil, as is well known inthe art. In some cases the sole constituents of the well-working fluidsmay be simply a petroleum oil and the FLCA. The latter may be presentfrom as little as 5 kg/m³ to as high as 150 kh/m³. The beneficial effecton fluid loss of the use of the FLCA may be observed even at the lowestconcentration. This is especially the case when the FLCA is added to thewell-working fluids containing other additives, of types to be mentionedhereinbelow.

Frequently, the well-working fluids will contain other additives, acommon one being water, often present from as little as 2% or 3% byvolume to as great as 40% to 60% by volume. It is desirable and commonto use a suitable emulsifying agent, which may be the calcium salt of aninexpensive fatty acid, e.g., calcium tallate, to emulsify the water inthe oil. An important feature of my invention, however, is that the FLCAare excellent emulsifying agents for any water which may be present inthe well-working fluids. It is important that such water be kept in theform of a good stable water-in-oil emulsion.

The presence of water in the well-working fluids serves to increase thedensity of the fluid somewhat since the water is heavier than the oilused; and it also helps to reduce filtration. Also it lowers the cost ofthe well-working fluid which is often an important item when largevolumes are used. Often water soluble salts such as calcium chloride areadded to the aqueous phase.

Weighting materials are routinely used in well-working fluids whereneeded, such as ground barite, calcium carbonate, siderite, iron oxide,ilmenite and the like. Suspending agents and viscosifiers such asorganophilic clays, asphalt, polymers and the like are commonlyemployed. Moreover, the well-working fluids may contain various oilsoluble or dispersible materials which function to keep the solids inthe well-working fluid from being wet with water.

Addition of one or more amino compounds to the well-working fluid mayadvantageously increase the thermal stability and emulsion stability ofthe well-working fluid.

The following nonlimiting examples illustrate the results and benefitsobtainable utilizing the FLCA of this invention in well-working fluidsas well as illustrating the preferred method of preparing the FLCA. Inthe examples, all percentages are by weight unless otherwise indicated.All data were obtained utilizing the American Petroleum Institute'srecommended testing procedures as set forth in API RP 13B.

EXAMPLE 1

250 grams of xanthan gum (Kelco XC Polymer) were thoroughly mixed with35 grams of commercial soybean lecithin. This sample was evaluated forits ability to decrease the fluid loss of Mentor 28 mineral oil bymixing the oil with 31.6 kg/m³ of the sample for 10 minutes with aMultimixer. The API fluid loss at room temperature was 7 cc.

This sample was evaluated at a concentration of 28.5 kg/m³ for itseffect on the properties of an invert oil emulsion drilling fluid. Thedata are given in Table 1.

                  TABLE 1                                                         ______________________________________                                                                  28.5 kg/m.sup.3                                                       Base Mud                                                                              Sample No. 1                                        ______________________________________                                        Initial Properties                                                            Plastic Viscosity, cp.                                                                            35        34                                              Yield Point, kg/m.sup.2                                                                           13        11                                              10-Second Gel Strength, kg/m.sup.2                                                                2         2                                               5-Minute Gel Strength, kg/m.sup.2                                                                 6         2                                               After Rolling for 16 Hours at 300° F.                                  Plastic Viscosity, cp.                                                                            35        33                                              Yield Point, kg/m.sup.2                                                                           12        6                                               10-Second Gel Strength, kg/m.sup.2                                                                3         2                                               5-Minute Gel Strength, kg/m.sup.2                                                                 9         4                                               HT-HP Fluid Loss at 300° F., cm.sup.3                                                      29        16                                              ______________________________________                                    

EXAMPLE 2

50 grams of alginic acid were mixed thoroughly with 7 grams ofcommercial soybean lecithin. This sample was evaluated at aconcentration of 28.5 kg/m³ for its effect on the properties of aninvert oil emulsion drilling fluid. The data are given in Table 2.

                  TABLE 2                                                         ______________________________________                                                           Base  28.5 kg/m.sup.3                                                         Mud   Sample No. 2                                         ______________________________________                                        Initial Properities                                                           Viscosity, cp.       30      31                                               Yield Point, kg/m.sup.2                                                                            12      14                                               10-Second Gel Strength, kg/m.sup.2                                                                 5       7                                                5-minute Gel Strength, kg/m.sup.2                                                                  9       10                                               Emulsion Stability, v.                                                                             2000+   1820                                             After Rolling for 16 Hours at 300° F.                                  Viscosity, cp.       33      42                                               Yield Point, kg/m.sup.2                                                                            9       17                                               10-Second Gel Strength, kg/m.sup.2                                                                 6       8                                                5-Minute Gel Strength, kg/m.sup.2                                                                  13      16                                               Emulsion Stability, v.                                                                             1250    1360                                             HT-HP Fluid Loss at 300° F., cm.sup.3                                                       21      14                                               ______________________________________                                    

The organophilic polymer adducts of this invention have utility in otherorganic liquids other than oil base drilling fluids. Thus they may beuseful in printing inks, foundry mold and core sands, foundry mold andcore washes, coatings, agricultural sprays, and other systems containinga major proportion of an oleaginous liquid.

What is claimed is:
 1. An organophilic polymer comprising an adduct of a cationic or anionic polysaccharide or derivative thereof and one or more phosphatides having the empirical formula

    R.sub.1 --CO--O--CH.sub.2 --CH(R.sub.2)--CH.sub.2 --Q      (I)

where: R₁ is an aliphatic group containing from 8 to 29 carbon atoms; R₂ is selected from the group consisting of H, OH, R₁ COO, and OP(O)(O⁻ zM^(a+))OZ; Q is selected from the group consisting of R₁ COO and OP(O)(O⁻ zM^(a+))OZ; Z is selected from the group consisting of xM^(a+), C₆ H₆ (OH)₅ and CH₂ --CH(Y)--N(R₃)(R₄)(R₅)y(A^(b-))_(v) ; Y is selected from the group consisting of H and COO(xM^(a+)); R₃, R₄, and R₅ are independently selected from the group consisting of H, aliphatic groups containing from 1 to 30 carbon atoms, and R₆ CO; R₆ is an aliphatic group containing from 1 to 29 carbon atoms; M is a cation selected from the group consisting of H, an alkali metal, an alkaline earth metal, ammonium, and mixtures thereof; A is an anion valence of b; y=0 or 1; w, x, and z=0 or 1/a where a is the valence of M; v=0 or a/b; and where Q is R₁ COO only when R₂ is OP(O)(O⁻ zM^(a+))OZ.
 2. The organophilic polymer of claim 1 wherein said cationic or anionic polysaccharide or derivative thereof is 13 selected from the group consisting of alginic acid, agar, carrageenan, cellulose, chitin, guar gum, gum arabic, gum ghatti, gum karaya, gum konjak, gum tamarind, gum tara, gum tragacanth, locust bean gum, pectins, starch, xantham gum, and mixtures thereof.
 3. The organophilic polymer of claim 1 wherein said cationic or anionic polysaccharide contains one or more monosaccharide units 13 selected from the group consisting of arabinose, fructose, galactose, galactopyranosyl, galacturonic acid, guluronic acid, glucuronic acid, glucose, glucoside, N-acetylglucosamine, mannuronic acid, mannose, pyranosyl sulfate, rhammose, and xylose, or a derivative of said polysaccharide.
 4. The organophilic polymer of claim 1, 2, or 3, wherein said phosphatide is a mixture of phosphatides where:R₂ =c R₁ COO+d OP(O)(O⁻ zM^(a+))OZ; Q=d R₁ COO+c OP(O)(O⁻ zM^(a+))OZ; R₁ is an aliphatic group containing from about 15 to about 17 carbon atoms; R₃, R₄, and R₅ are independently selected from the group consisting of H, CH₃ and R₁ CO; and c≧0, d≧0, and c+d=1.
 5. The organophilic polymer of claim 1, 2, or 3 wherein said phosphatide is a mixture of phosphatides obtained from a vegetable oil. 